opendaylight/md-sal/sal-distributed-datastore/src/main/java/org/opendaylight/controller/cluster/databroker/actors/dds/LocalReadOnlyProxyTransaction.java

   1 /*
   2  * Copyright (c) 2016 Cisco Systems, Inc. and others.  All rights reserved.
   3  *
   4  * This program and the accompanying materials are made available under the
   5  * terms of the Eclipse Public License v1.0 which accompanies this distribution,
   6  * and is available at http://www.eclipse.org/legal/epl-v10.html
   7  */
   8 package org.opendaylight.controller.cluster.databroker.actors.dds;
   9
  10 import com.google.common.base.Preconditions;
  11 import com.google.common.base.Verify;
  12 import java.util.Optional;
  13 import java.util.function.Consumer;
  14 import javax.annotation.concurrent.NotThreadSafe;
  15 import org.opendaylight.controller.cluster.access.commands.CommitLocalTransactionRequest;
  16 import org.opendaylight.controller.cluster.access.commands.ModifyTransactionRequest;
  17 import org.opendaylight.controller.cluster.access.commands.PersistenceProtocol;
  18 import org.opendaylight.controller.cluster.access.concepts.Response;
  19 import org.opendaylight.controller.cluster.access.concepts.TransactionIdentifier;
  20 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier;
  21 import org.opendaylight.yangtools.yang.data.api.schema.NormalizedNode;
  22 import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTreeSnapshot;
  23
  24 /**
  25  * A read-only specialization of {@link LocalProxyTransaction}.
  26  *
  27  * @author Robert Varga
  28  */
  29 @NotThreadSafe
  30 final class LocalReadOnlyProxyTransaction extends LocalProxyTransaction {
  31
  32     private final DataTreeSnapshot snapshot;
  33
  34     LocalReadOnlyProxyTransaction(final ProxyHistory parent, final TransactionIdentifier identifier,
  35         final DataTreeSnapshot snapshot) {
  36         super(parent, identifier, false);
  37         this.snapshot = Preconditions.checkNotNull(snapshot);
  38     }
  39
  40     LocalReadOnlyProxyTransaction(final ProxyHistory parent, final TransactionIdentifier identifier) {
  41         super(parent, identifier, true);
  42         // It is an error to touch snapshot once we are DONE
  43         this.snapshot = null;
  44     }
  45
  46     @Override
  47     boolean isSnapshotOnly() {
  48         return true;
  49     }
  50
  51     @Override
  52     DataTreeSnapshot readOnlyView() {
  53         return Preconditions.checkNotNull(snapshot, "Transaction %s is DONE", getIdentifier());
  54     }
  55
  56     @Override
  57     void doDelete(final YangInstanceIdentifier path) {
  58         throw new UnsupportedOperationException("Read-only snapshot");
  59     }
  60
  61     @Override
  62     void doMerge(final YangInstanceIdentifier path, final NormalizedNode<?, ?> data) {
  63         throw new UnsupportedOperationException("Read-only snapshot");
  64     }
  65
  66     @Override
  67     void doWrite(final YangInstanceIdentifier path, final NormalizedNode<?, ?> data) {
  68         throw new UnsupportedOperationException("Read-only snapshot");
  69     }
  70
  71     @Override
  72     CommitLocalTransactionRequest commitRequest(final boolean coordinated) {
  73         throw new UnsupportedOperationException("Read-only snapshot");
  74     }
  75
  76     @Override
  77     Optional<ModifyTransactionRequest> flushState() {
  78         // No-op
  79         return Optional.empty();
  80     }
  81
  82     @Override
  83     void applyForwardedModifyTransactionRequest(final ModifyTransactionRequest request,
  84             final Consumer<Response<?, ?>> callback) {
  85         commonModifyTransactionRequest(request);
  86         abort();
  87     }
  88
  89     @Override
  90     void replayModifyTransactionRequest(final ModifyTransactionRequest request,
  91             final Consumer<Response<?, ?>> callback, final long enqueuedTicks) {
  92         commonModifyTransactionRequest(request);
  93         enqueueAbort(callback, enqueuedTicks);
  94     }
  95
  96     private static void commonModifyTransactionRequest(final ModifyTransactionRequest request) {
  97         Verify.verify(request.getModifications().isEmpty());
  98
  99         final PersistenceProtocol protocol = request.getPersistenceProtocol().get();
 100         Verify.verify(protocol == PersistenceProtocol.ABORT);
 101     }
 102 }